Baling agricultural produce is a well-known and frequently used practice throughout the world. Various methods, techniques, products, materials, and equipment have been used to harvest, bale and wrap agricultural produce.
In recent years, knitted nets and films, including those constructed of polypropylene and polyethylene, have been replacing the wire/sisal twine and baling twine which have been traditionally used. However, regardless of the material being used, the wrapping material must maintain the bale within the wrapping until the user opens the bale for use in its designated purpose, such as: distribution of the agricultural product in the targeted area (e.g., manger or stall); feeding and/or processing; or the like.
Wrapping materials made from plastic films provide improved protection of the wrapped produce from the forces of nature, as it is common for agricultural produce to remain wrapped in an open field for a time period that could vary from several months to more than a year before use. One such plastic film is commonly known as “sticky film,” which includes plastic films that inherently cling to itself or plastic films that include an adhesive applied to the surface area of at least one side of the plastic wrap or across the entire lateral dimension.
However, there are many problems noted in the art with respect to wrapping materials with the adhesive disposed at the lateral edges and along the longitudinal length of such wrapping material. For instance, the ease and progress of the wrapping material through the baler is greatly impeded by frictional type interaction that decreases productivity and increases costs. Additionally, when the adhesive is applied on one entire side, the strength of the adhesive must be limited since the film must still be allowed to unwind during wrapping of an item.
Moreover, there are various forces exerted on the wrapping material, which cause the wrapping material, particularly the tail edge, to come loose after an item is wrapped. Shearing and peeling are examples of some of these forces exerted on wrapping material during wrapping. In addition, if the wrapping material is used outdoors, exposure to the extremes of temperature, moisture and especially wind will cause additional problems with adhesion of the tail edge of wrapping material.
Over the years, in an attempt to solve the problem of fastening the bales wrapped with such films, a number of solutions have been proposed, such as described in U.S. Pat. Nos. 6,787,209, 7,541,080, and 8,071,196, PCT Application No. PCT/IB2005/003589, and U.S. application Ser. Nos. 12/113,720 and 13/734,428, all of which are incorporated by reference as if fully set forth herein. Such proposed solutions entailed, for example, the use of adhesive at the end of the wrap, or the use of fasteners (e.g. Velcro).
Although this type of wrapping material tends to have increased adhesive qualities, especially at the tail edge of the wrapping cycle, problems have been experienced with the portions of the wrap sticking to each other. This occurs, for instance, when wrapping units are wound onto a bobbin during the manufacturing process, or otherwise organized for use during the wrapping process. In addition, after the adhesive areas are exposed but prior to wrapping, dust and other particulate matter may decrease the adhesiveness of any adhesive areas. Further, those solutions proposing the use of fasteners and other non-adhesive connectors suffer from the disadvantages of being unreliable and financially unviable.
Thus, there is clearly a need in the art for a wrapping material that achieves the benefit of having increased adhesive qualities at the tail edge of the wrapping cycle, but without suffering from the aforementioned disadvantages, including the increased difficulty during both the manufacturing and wrapping processes, and the adverse effects of dust and other particulate matter on the quality of the adhesion.